Bit-brace extension



'March 10, 1925.

C. BQDMER BIT BRACE EXTENSION Filed April 9, 1924 with a bit brace, and by means of which the l nt-madman 10, 1925.

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I Application maa ru'a, 1m. serial Illo. 706,168.

To' cll'iohom it may concern:

Be it known that I, CmusrrAN Bonner, a citizenof the United States and a resident ofNew Britain, county of Hartford, State of Connecticut, have invented certain new a and useful Im rovementsin Bit-Brace Ex- 7 fication.

I ous features of novelty and advantage andtensions, of w ich the following is a speci- This invention relates to a holder or extension adapted to be used in connection bit is extended to enable the user to bore holes through structures where the ordinary bit, without the use of an extension, will not reach. 1 w

The aim oftheinvention is to provide an extension or holder 0f this sort having variwhich islparticularly characterized by its extreme strength and durability, the-sun .plicity' in construction, its effectiveness in operation,-and the readiness with which. the parts'maybe assembled or replaced when 1161 Li: 2 If; f

Other objects will .be in part obvious and in part'pomted out more in deta l hemmafter.

pendedclailm The invention accordingly consists in the features of construction, combination of elements and arrangement of parts 'whlch will be' exemplified in the construction hereinafter set forth, and the sec e of the application of which will be in cated in t e ap- In' the accompan g drawing, wherein I have shown, for i ustrative purposes, one

embodiment which the present invention may take: i

Referring to the drawing in detail, m

improved holdercomprises an extension portion roperhaving a shank a of suitable lengt and. a socket or collet b at one end of the shank. Preferably, the socket and shank are into being formed from a single iece 0 steel so that it has great strengt and durability and the socket can-' not work loose from the shank durin the boring operation. The end'of the ank threaded portion 6 llooftheshanksoasto opposite the socket is squared and tapered,

as at 10, so as to be received and clamped by the usual jaws or chuck with which the ordinary bit brace is rovided. The socket or collet is of genera ly tapering construction and is longitudinally slotted so as to provide a plurality of spring fingers, as shown'most clearly in Fig. 2. The shank a, ad acent the inner end of the socket b, is of somewhat larger diameter than the ren ammgportion of the shank and is provided Wlth a thread 11. Preferably, the root diameter of the thread is slightly less than, and the outside diameter is substantially the same as, the eatest diameter of the squared end 10. I? desired, the exten- S1011 proper, which s provided with the socket, shank, and an intermediate threaded portion, may be formed ofmore than two pieces of steel which are welded together so ing the boring operation. The letter a designates a sleeve having a sliding fit at its rear end on the threaded portion. 11 and having its forward end internally ta red as at 13 to correspond to and closely t the tapered collet b. (1 indicates a-nut having at one end an internal thread adapted to engage with .the threads 11 on the shank. The nut, at its rear end, has a smooth bore and constitutes a skirt for concealing the when the nut is in advanced position.

As seen from Fig. 3, the threaded portion of the nut is prov ded with longitudinally extending grooves 15 spaced apart corresponding to' the edges of the squared end rmit the nut to he slipped over the end 0 the shank when it is desired to assemble the nut in position or take it ofi. Between the nut d and the sleeve 0 is a rin e which serves to reduce the friction an which gives a pleasing ap rance.

mm the foregoing description, it will be seen that my improvedextension comprises a relatively few number of arts, each of which, while being very sim e in construction, vel'iy;e strong and urable. These arts may economically manufactured.

erod, comprising the shank, the socket and the intermediate threaded portion, be-

' ing integral from end to end, is enabled to .if it is 1 parts, it is only necessary unscrew the nut from the threaded portion and then sli the parts over the s uared end 10.

is many changes coul .be made in the above construction and many apparently widely diflerent embodiments of this invention could be made without departing from the scope thereof, it'is intended that all mattercontained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the lan uage used in the following claim .is inten ed to cover all of the generic and-specific features of the invention herein described and all statements of the scope of The sleeve 0 and the nut the invention which, as-a matter of language, might be said to fall therebetween.v

I claim-as my invention: v A bit brace extension including a shank, a socket, and an intermediate threaded portion integral with one another, the rear equals the dia onal of the squared end, and

a nut screwe onto said threaded portion and adapted to advance said sleeve in a direction to contract the jaws, said nut having a skirt at its rear end and having on its threaded portion longitudinally extending grooves of the depth of thethread adapted to receive the corners of the squared end of said shank whereby the nut may be slipped over said end.

CHRISTIAN BODM'ER. 

